Patent GB-428766-A (GB)
Title: Improvements in and relating to hydraulic transmission devices
IPC: F16H47/08
Filed: 1933-10-09
Abstract: 428,766. Hydraulic transmission of power. LAVAUD, D. S. DE, 82, Rue de la Jonquiere, Paris. Oct. 9, 1933, No. 27788. Convention date, Oct. 8, 1932. [Class 69 (ii)] A hydraulic transmission device of the type comprising a vaned driving motor or pump, a vaned driven rotor or turbine, and a third vaned rotor having guide vanes for directing the working fluid between the other two rotors has automatically operated means for preventing reverse rotation of the third guide rotor when the speed of the turbine falls below a predetermined valve relatively to the pump. The driven rotor 4 is secured to a hub 60 keyed on a shaft 7 which is hollow at the end remote from the driving shaft 3 to receive the reduced end of the driven shaft 28. The guide rotor 10 is free to rotate on a ball bearing 17 between it and the hub 60 and is provided with an inwardly directed annular flange 18 adapted to engage with a disc 19 splined to a sleeve 22 secured to the fixed casing 21 of the device: a spring 20 normally holds the disc 19 clear of the member 18. The web 23 of the guide rotor is provided with a number of perforations 23<a> that allow a free passage for the circulating fluid and when the speed of the device is low, the pressure of the fluid passing through these perforations forces the disc 19 against the pressure of the spring 20 into engagement with the flange 18 thus locking the guide rotor against rotation. A gear pressure pump 30, 31 supplies liquid through conduits 70 to enter the vanes 5 of the driving rotor 1 ; the casing 21 serving as a reservoir for the pump. The casing 21 and the shaft 7 have conical parts 35, 36 adapted to be engaged alternatively by a coupling member 37 provided with teeth on its periphery corresponding to similar teeth 34, 8 on the adjacent parts of the casing 21 and the shaft 7 respectively and carrying a drum 40 toothed internally to slide on these teeth. A disc 49 extends from one end of the drum and carries rods 50 that drive a cage 59 in which spindles 58 are mounted each carrying three satellite pinions 51, 52, 53 the pinion 52 being smaller than the others according to the gear ratio desired. The pinions 51, 52, 53 mesh respectively with teeth 8 on the shaft 7, teeth 54 on the driven shaft and teeth 56 on the hub of a drum 57 on the periphery of which a brake jaw 61 may act. In operation with the coupling 37 in its preposition on the driving shaft 3 commencing to turn the pump 30, 31, is actuated and liquid flows through the vanes of the members 1, 4 and 10, and the driven rotor 4 transmits motion to the shaft 7 which in turn drives the pinions 51 but, as the cage 59 is free to rotate, motion is not transmitted to the shaft 28 : as, owing to the slow rotation at first the pressure of the liquid passing through the perforations 23<a> is high, the disc 19 is moved laterally to lock the member 10 against rotation; as the speed increases the pressure falls and the member 10 is freed to rotate in the same sense as the members 1 and 4. If the drum and coupling member are moved to the right the cage is locked to the shaft 7 by the member 40 engaging the teeth 8 and the shaft 28 is driven directly from the shaft 7 ; if the drum 40 and the coupling member 37 are moved to the left the rotation of the cage 59 is stopped and the shaft 28 is driven through the teeth 9 and the pinions 51, 52, 54. In either of the two preceding cams if the brake jaw 61 is brought into engagement with the drum 57 direct braking is effected : if however the drum is engaged by the brake jaw with the coupling member in neutral position the pinion 53 is prevented from rotating thus causing the shaft 28 to be driven in the reverse direction. The drum 40 is connected through a yielding connection 41 with the coupling member 37 so that the latter engages the cone surfaces 35, 36 first and then the teeth of the drum engage the corresponding teeth 8, 34. In modifications (1) the guide member 10 is held against backward rotation by pawls ; (2) a disc corresponding to the disc 19 is moved by the suction of a driving motor forming the prime mover ; (3) the disc is provided with a brake rim on which a brake shoe, controlled automatically, may act ; (4) an automatically controlled electromagnetic device may be employed to actuate a friction member. Specification 408,098 is referred to. Reference has been directed by the Comptroller to Specification 249,199, [Class 69 (ii)].